1. Field of the Invention
A hydralically operated clutch modulator for modulating the rate of engagement of a hydraulic clutch is provided.
2. Description of the Prior Art
Numerous prior art patents exist that attempt to provide clutch engagement modulation. There are patents, such as U.S. Pat. No. 3,351,170 to E. Hengstler, which show hydraulic clutch packs downstream of a modulating valve interposed between the clutches and a hydraulic fluid supply pump have been investigated and found operatively different when compared to the instant invention.
Prior art devices are also known where pressure is provided behind a poppet valve equivalent to pressure provided to the clutch packs until the clutch packs are fully pressurized. When fully pressurized the poppet valve also closes preventing further pressure buildup in the clutch packs. This is a rather typical embodiment but it does not allow for flow past the modulator valve (or the poppet valve) to the torque converter as does the instant invention.